1. Field of the Invention
The invention relates to a screwdriver having multiple bits selectable for use one at the time and the bits being stored inside a handle of the screwdriver.
2. Description of the Prior Art
In the past, different approaches have been tried to provide screwdrivers having a plurality of bits accessibly stored in a housing of the screwdriver, the housing generally also serving as the screwdriver gripping handle.
U.S. Pat. No. 3,750,729 (Lemieux) shows a multiple driver tool having a chamber for holding a plurality of screw drivers. Each driver has a guided slide, by means of which the driver can be selectively moved to a passage extending away from an end of the chamber. Guide means in the chamber directs each driver towards and into the passage during movement of that driver. Each driver is long enough, that when in the passage, it projects beyond the end of the tool. Each driver is attached to a flexible actuator, which can be used to slide the driver from a stored position, inside the tool, to an extended position, where the tip of the driver protrudes outside the tool. In the extended position, wings arranged at the sides of the driver engage slots in the tool housing, to provide a torque transfer from the tool to the driver. Simultaneously, the driver is held in the extended position by a spring biased pin latch engaging a groove in the driver. The user of the tool has to release the pin latch, by pressing a lever disengaging the pin latch from the groove, to slide the driver back into the retracted position. The drivers (bits) are required to have the specially shaped groove (with a stepped surface to catch on the pin latch) and the torque transfer wings, making it necessary to manufacture drivers that are non-standard and therefor more expensive. The latch mechanism, with its lever operated latch pin, is also seemingly fragile.
U.S. Pat. No. 5,325,745 (Koehler) shows a hollow screwdriver housing with a handle portion at the rear of the housing. The front of the housing is open and individual screwdriver bits are slidable back and forth from a stored position angularly located inside the housing in a retracted position, to a in-use position where a hexagonal end of the screwdriver bit is held by a central column attached to the handle and where the working tip of the screwdriver bit extends outside the housing. Each bit has an actuator attached to it, the actuator extending through an opening in the housing. The bit may be moved from a storage position inside the handle by pressing the pre-selected actuator, moving the bit outside of the open end of the housing, holding the actuator down and retracting the bit to engage a recess of the central column. The substantially long-reaching bit is held by the recess only, for both torque transfer and lateral support. The actuator attaches substantially to the middle of the bit, to provide a small amount of additional lateral support. If any side-ways pressure is applied on the bit, by the user exerting force via the handle, it seems apparent that the bit according to this construction lacks sufficient lateral support for high-torque applications. Since substantially long-reaching bits are used, the space requirements inside the handle are large, and to provide a suitably well-anchored central column, the length of the handle is also large. The end result is a tool of substantial length.